Why are earbud wires for an mp3 player coated with plastic
1, to better conduct the sound
2, to insulate the wires
3, so they look good
4, so they dont break

2) they add the insulation to better the durability or the earbuds

resonant frequency

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures